The iPhone 5S and 5C went on sale Friday, Sept. 20, and on Monday morning Apple announced that it had sold a “record-breaking 9 million new iPhone 5S and 5C models.”

In September 2012, Apple made the iPhone 5 available for preorder and sold 2 million in the first 24 hours and 6 million over 10 days. When it made the iPhone 4S available for preorder in October 2011, it sold 1 million the first day, surpassing the single-day record of 600,000 units set by the iPhone 4 in 2010.

Analysts had no expectation that the iPhone 5S and 5C would perform as they did. With the phones not a major departure from the iPhone 5, most analysts forecast sales between 5 million and 6 million. BMO Capital Market's Keith Bachman, speaking with Bloomberg, and Citigroup’s Glen Yeung had offered likely the highest forecasts, of 7.75 million units.

That Apple didn’t make the iPhone 5S, its newest flagship device, available for preorder was a first and one that Piper Jaffray analyst Gene Munster suspected was due to a shortage of units. In a Sept. 19 research note, Munster told investors that due to the Touch ID fingerprint reader on the 5S, Apple was expected to be more “production constrained” than with previous models, and its decision to not offer the 5S for preorder was to prevent customers from “immediately seeing delivery times for 2-plus weeks out.”

On the morning of Sept. 20, Apple began selling the phones online at 3 a.m. ET and by 7 a.m. had run out of gold 5S models, updating its site to say the phones would ship in “7 to 10 business days.”

By 10 a.m. ET, the site was instead promising gold models simply in “October,” while the AT&T site was updated to say that silver and gray models would ship in 7 to 10 days but that gold models wouldn’t ship for possibly 28 business days.

eWEEK visited several sales locations and found that carriers hadn’t received all models and versions—a Sprint store in Brooklyn had received only 64GB gray iPhone 5S handsets—and the gold 5S had sold out near-instantly at the Apple locations, which had received all models, but limited units. At all locations, the 5C was in supply.

Apple made the 5C available for preorder on Sept. 14, but made no announcement about the response the device had received. (Trip Chowdhry, with Global Equities Research, said in a Sept. 23 report that announcing 5C preorder results wouldn’t have made sense, given the Sept. 18 launch of iOS 7 and the Sept. 20 sales date for both the 5S and 5C.)

The initial response to the 5C was chilly, particularly in China, where it was expected to address a healthy market for lower-priced devices but instead came out well above the expected price point. In another first, the 5C and 5S became available in China, the world’s largest smartphone market, the same day as in the United States—a move that surely helped boost opening-weekend sales.

Chowdhry expects the 5C will prove popular with kids, due to its $99 price point in the United States (Sprint is currently offering it free to new customers), plastic cover and bright colors.

Parents feel less worried giving their kids the plastic device, he wrote in the Sept.23 research note, and said that it was a natural extension of the iPads their kids are already using in school.

Piper Jaffray's Mustertold investors that likely 95 percent of the customers who waited online for a new iPhone this weekend were waiting for the iPhone 5S.

Apple, in its Sept. 23 statement, added that 200 million iOS devices are now running iOS 7, and its new iTunes Radio has already had more than 11 million unique listeners.

“The demand for the new iPhones has been incredible, and while we’ve sold out of our initial supply of iPhone 5S,” Apple CEO Tim Cook said, “stores continue to receive new iPhone shipments regularly. We appreciate everyone’s patience and are working hard to build enough new iPhones for everyone.”